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Back to the future of industrial research: Early double-impact research at General Electric, AT&T and DuPont (1902–1948)
No full textInternational audienceAfter the corporate research bloodbath that occurred in the 1990s, there was a need for firms to reinvent the management of corporate research. Although several explanations exist for how corporate research can fail, management science lacks models that can account for successful management. This paper addresses this gap by proposing such a model. Methodologically, this paper adopts a historical approach because it is particularly adaptable to a) assessing success on clearly evaluated facts at several time horizons and b) using rich, longitudinal, well-controlled data related to how management occurred in the past. This paper thus discusses the strategic role and inner functioning of corporate research at General Electric, AT&T Bell Labs and DuPont. These four cases demonstrate that successful corporate research can be attributed to the existence of simultaneous and bidirectional links between corporate research, strategy, new product development and the scientific community. These sixfold links constitute conditions for corporate research that are strategically and scientifically relevant. The results show that, contrary to widespread belief, 1) research is carefully integrated into the firm's strategy, and 2) GE, AT&T and DuPont provide examples of the fruitful interaction between fundamental research and new product development that leads to new products and scientific breakthroughs. The present paper thus contributes to the ongoing debates on the role and management of corporate research, particularly “double-impact” research
Understanding the socio-economic patterns driving the adoption of rooftop photovoltaic systems : a preliminary literature review
No full textThis literature review examines the key factors influencing the adoption of residential photovoltaic (PV) rooftop systems. Economic research approaches this topic from both macroeconomic and microeconomic perspectives, identifying a range of determinants, particularly socioeconomic and financial, that influence individual decisions. This findings reveal a complex interaction between these factors, highlighting how they can significantly affect the effectiveness of public incentive policies. A better understanding of these dynamics is crucial for designing policies that are both efficient and socially equitable in promoting the energy transition.</div
Stretching and breakup of two-dimensional falling Newtonian sheets
No full textInternational audienceThis theoretical and numerical study investigates the stretching and the subsequent breakup process in a Newtonian sheet that falls from a slot in ambient air under gravity. We perform two-dimensional numerical simulations based on a variational multiscale approach devoted to multiphase fluid flows. The results are analyzed by considering the sheet stretching dynamics, energy transfers, and scaling laws. Three flow regimes associated with the early times of the stretching process are highlighted: gravito-inertial (free fall); gravito-viscous; and mixed gravito-inertio-viscous. In late times, the sheet becomes balanced by a competition between inertial and capillary stresses. The findings are summarized in two-dimensional diagrams that correlate the sheet breakup time and the generation of satellite objects after the liquid fragmentation with different flow regimes using the important dimensionless parameters of the problem
Modelling the error structure in Urban Building Energy Models with a Gaussian Process-based approach
No full textInternational audienceUrban Building Energy Models (UBEM) support urban-scale energy decisions and have recently been applied to use cases requiring dynamic outputs, like grid management. Yet their predictive capability outside limited validation experiments (VEs) is seldom quantified. We present a Gaussian‑process (GP) framework that estimates both model bias and uncertainty when a UBEM is applied under conditions that differ from those observed during validation. The workflow: (i) assemble a training set that links VE conditions to the corresponding validation errors; (ii) select predictors and train a GP model; (iii) evaluate interpolation and extrapolation skills by k-fold cross validation. Applied to the Blagnac (France) district heating network with the UBEM DIMOSIM, GP models effectively capture the inherent structure of UBEM error and uncertainties: error increases with load fluctuations and extreme weather, while synergistic effects between solar irradiance and outdoor temperature are uncovered. The approach therefore offers a data‑efficient means to quantify UBEM accuracy and to highlight scenarios where additional measurements would most reduce uncertainty
Decarbonisation of industry and the energy system: Exploring mutual impacts and investment planning
No full textInternational audienc
Simplified dynamic heat exchanger models for heat recovery steam generators
No full textInternational audienceMonitoring power plants necessitates sophisticated methods and reliable dynamic models, especially with the increasing flexibility demand. The primary challenge of this work is to develop a modelling strategy for heat recovery steam genera-tors (HRSG) that enables simple yet accurate simulation of their dynamic behaviour, accounting for the delayed response of their heat exchangers to load variations caused by high thermal inertia. The proposed modelling methodology aims to build models suitable for monitoring power plants based on a set of sensor measurements, which can realistically be found in a power plant. This approach eliminates the need for extensive system design information, which may not always be accessible to the modeller. First, fully detailed, pseudo three dimensional Modelica model of the monophasic heat exchang-ers is developed. The model is then simplified progressively while the impact on accuracy is assessed. A more simplified model is later developed by assuming a lumped global heat transfer coefficient and a mass. The simplified model provides promising results, demonstrating a good compromise between simple calibration process and accuracy. A model of the evaporator is also presented and validated based on literature. Finally, a qualitative analysis of the full HRSG model is conducted. The dynamic behaviour as well as the time constants of the heat exchangers are analysed. The results demon-strate a good agreement with the expected physical behaviour
Using One Wind Farm as a Reference to Estimate the Energy Production of Another: Insights from a Probabilistic Analysis
No full textInternational audienceState-of-the-art methods for modeling wind farm energy production follow a two-step approach: modeling the wind resource and then the farm’s conversion of wind into power. These models carry uncertainty due to both accuracy limitations and the stochastic nature of wind. Probabilistic modeling addresses this by assigning probabilities to different production levels by propagating error distributions. We extend this probabilistic framework to two dimensions by examining the joint probability distribution of energy production at two wind farms in the same region but with different configurations. When operational data from one farm is available, it can inform the expected production of the second, quantifying the uncertainty reduction. This is particularly relevant for repowering projects or developments near existing farms. Existing approaches focus on short-term prediction and rely on operational data, which is unavailable for future farms. Instead, joint production must be estimated using a physics-based a priori approach. While joint distributions of some error sources exist, others remain unassessed, and no model propagates these joint errors to energy production. We address this gap by developing a physics-based framework to propagate joint uncertainties and assess its impact through a case study
Développement d’un modèle cinétique et thermodynamique pour l’étude de la lixiviation d’un minerai latéritique
No full textInternational audienc
Steady-state neuron-predominant LINE-1 encoded ORF1p protein and LINE-1 RNA increase with aging in the mouse and human brain
No full textReviewed Preprint published in e-Life https://elifesciences.org/reviewed-preprints/100687v1International audienceRecent studies have established a reciprocal causal link between aging and the activation of transposable elements, characterized in particular by a de-repression of LINE-1 retrotransposons. These LINE-1 elements represent 21% of the human genome, but only a minority of these sequences retain the coding potential essential for their mobility. LINE-1 encoded proteins can induce cell toxicity implicated in aging and neurodegenerative diseases. However, our knowledge of the expression and localization of LINE-1-encoded proteins in the central nervous system is limited. Using a novel approach combining atlas-based brain mapping with deep-learning algorithms on large-scale pyramidal brain images, we unveil a heterogeneous, neuron-predominant and widespread ORF1p expression throughout the murine brain at steady-state. In aged mice, ORF1p expression increases significantly which is corroborated in human post-mortem dopaminergic neurons by an increase in young LINE-1 elements including those with open reading frames. Mass spectrometry analysis of endogenous mouse ORF1p revealed novel, neuron-specific protein interactors. These findings contribute to a comprehensive description of the dynamics of LINE-1 and ORF1p expression in the brain at steady-state and in aging and provide insights on ORF1p protein interactions in the brain
Imagerie des structures internes d’un glissement de terrain par une approche couplée gravimétrie - tomographie de résistivité électrique
No full textInternational audienceL’imagerie des structures internes des glissements de terrain reste un défi important pourcaractériser la dynamique des instabilités de versant. Cette étude porte sur l’imagerie interned’un glissement de terrain situé sur la bordure sud des Causses du Larzac (France) et soumis àdes épisodes de pluie intense. Nous proposons ici une approche originale combinant des mesuresde résistivité électrique et de la micro-gravimétrie, et qui s’appuie également sur des données deforage et des observations géomorphologiques de surface. Les résultats obtenus mettent en évi-dence les dépôts de pente caractérisés par une forte résistivité électrique et une anomalie négativede densité. Ces dépôts ont une épaisseur moyenne de 30 m avec des variations latérales allantde 15 à 50 m dues à la géométrie complexe de l’interface entre les colluvions et les formationssous-jacentes ainsi qu’à la présence de blocs calcaires en profondeur. Les valeurs de porositéapparente estimées pour ces colluvions sont comprises entre 0,05 et 0,23, suggérant une capac-ité de stockage élevée et de possible variations importantes de la pression interstitielle lors defortes précipitations pouvant induire des mouvements de pente. Cette étude souligne la com-plémentarité de la micro-gravimétrie avec les méthodes géophysiques conventionnelles, telles quela tomographie de résistivité électrique, sismique ou les diagraphies pour imager les structuresinternes. La gravimétrie offre une vision plus directe de la densité de la roche et de la porositéapparente associée, qui sont essentielles pour comprendre la dynamique interne des glissementsde terrain